1. Field of the Invention
The present invention relates to fluid heaters and more particularly pertains to a new fluid heater system with a heater assembly that is tiltable for facilitating the performance of maintenance on the heater assembly and has relatively cooler exterior surfaces for safer operation.
2. Description of the Prior Art
Devices for pressurizing and heating fluid are known in the art. One type of fluid heating device uses combustion of a fuel in a combustion chamber to heat fluid moving through a length of tubing located in the combustion chamber. Typically, a burner is located at one end of the combustion chamber, and one or more coils of the tubing are typically located in the chamber toward the other end of the chamber. The burner directs a flame toward and over the coils of tubing. Some types of fluid heaters position the burner below the combustion chamber, and the burner fires upward toward a coil positioned above the burner. This arrangement is highly preferable for a variety of operational reasons but places a significant maintenance hardship on user of the devices.
Significantly, positioning of the burner on the bottom of the chamber places the burner beneath the combustion chamber in a difficult orientation for performing periodic maintenance on the burner. Support framing for the combustion chamber typically extends below the burner and thus further restricts access to the burner. In order to avoid having to crawl under the fluid heating device for servicing the burner, one approach has been to periodically invert the entire fluid heating device during the servicing. Because of the presence of fuels, cleaning solutions, and engine lubricating fluids often held in tanks on the fluid heating device, tipping of the device is disfavored because the possibility of spilling the liquids requires that all of the fluids be removed prior to each servicing, and often requires awkward propping of the device in the inverted position. As these devices typically weigh between 350 and 800 pounds, any attempt to tip them is both difficult and dangerous.
Another approach for facilitating servicing of the burner has been to permanently orient the combustion chamber of the device with the burner and the coil of tubing at substantially the same vertical level, so that the burner directs the flame in a generally horizontal direction toward the coils. Since the burner is essentially located beside of the combustion chamber, the burner is generally more accessible for periodic maintenance. However, with the tubing coiled about a horizontal axis, the tubing is difficult, if not impossible, to completely drain of fluid when necessary, such as for preparing the fluid heater device for maintenance on the coil of tubing or exposure to freezing temperatures, or to prevent corrosion during a period of extended non-use.
A further challenge presented by conventional fluid heaters employing a combustion chamber is the danger of burning or injuring the personnel working closely to the surfaces of the heater assembly, especially those exterior housing surfaces shrouding the combustion chamber in which the fuel is burned. Typically, insulation is positioned inside of the exterior housing surfaces in an attempt to resist heat transfer to the housing surfaces for keeping the exterior surfaces cooler than the hot surfaces of the combustion chamber. However, the use of insulation often fails to keep the housing surfaces cool enough to be safe to touch without injuring the skin of the operating personnel. Furthermore, simply adding enough additional layers of insulation to be effective produces a device that is excessively bulky, and the heat dissipated through the insulation is wasted.
These problems presented by conventional fluid heater designs have significantly impaired the safe use and regular maintenance of known fluid heaters.
In view of the foregoing disadvantages inherent in the known types of fluid heaters now present in the prior art, the present invention provides a new fluid heater system with a heater assembly design that facilitates the performance of maintenance on the heater assembly and permits safer operation of the heater assembly.
To attain this purpose, the present invention generally comprises a support frame and a heater assembly mounted on the support frame. The heater assembly comprises a combustion chamber and a burner apparatus for burning fuel in the combustion chamber. The heater assembly is pivotally mounted on the support frame for permitting pivoting of the heater assembly in a substantially vertical plane with respect to the support frame such that the heater assembly is pivotable between an operational position and a maintenance position. The operational position is characterized by a central axis of the combustion chamber being oriented in a substantially vertical direction and the maintenance position is characterized by the central axis being rotated from the substantially vertical direction toward a generally horizontal direction. A locking structure may be provided for selectively locking the heater assembly with respect to the support frame in the operational position and in the maintenance position. The combustion chamber has a chamber perimeter wall defining a chamber interior, and the chamber perimeter wall has an outer surface. A heating conduit for carrying fluid for heating by the combustion chamber is provided, and the heating conduit has an inlet and an outlet. The heating conduit has a preheating portion adjacent to the inlet, and the preheating portion extends about the outer surface of the chamber perimeter wall of the combustion chamber for absorbing heat from the chamber perimeter wall of the combustion chamber.
There has thus been outlined, rather broadly, the more important features of the invention in order that the detailed description thereof that follows may be better understood, and in order that the present contribution to the art may be better appreciated. There are additional features of the invention that will be described hereinafter and which will form the subject matter of the claims appended hereto.
In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting.
As such, those skilled in the art will appreciate that the conception, upon which this disclosure is based, may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.
For a better understanding of the invention, its operating advantages and the specific objects attained by its uses, reference should be made to the accompanying drawings and descriptive matter in which there are illustrated preferred embodiments of the invention.